Jacob a



J. A. L. MULLER.

TYPE WRITING R|BBON. APPLICATiON FILED MAY, 1919.

1 20,634. Patented Nov. 4, 1919.

-INVEN OR I (v zier ATTORNEY JACOB A. L. MOLLER, OF NEW YORK, N. Y.,ASSIG-NOR TO ROSE & FRANK COMPANY, A.

CORPORATION OF NEW YORK.

TYPE-WRITIIjT G RIBBON.

Specification of Letters Patent.

Patented Nov. 4, 1919.

Application filed May 14, 1919. Serial No. 297,089.

is to produce a better ribbon, one which will lieflat in use.

In the drawings, which are merely illustrative,

Figure 1 is a portion of a ribbon (threads exaggerated), and a Fig. 2 isa schematic representation of a gum-applying machine which may be used.

Heretofore typewriter ribbons have been made of awoven cotton fabric,and woven silk has been proposed, but as made they are open to variousobjections, and no. adequate diagnosis seems to have been made of theunderlying causes of some of the defects inherent 1n them, or of theremedies for such defects.

A typewriter ribbon, to be entirely satisfactory, must lie flat on themachine, not only when first applied but when subjected to the poundingof the type and atmospheric changes. If it wrinkles, due tounequal-contraction or other causes, it gives trouble. It must bevery-thin and flexible, and should not be unduly aifected by atmosphericmoisture.

A cotton fabric woven in a narrow strip has been used, and silk of someindefinite kind and characteristics has been proposed, but when woveninto a narrow strip each is open to various objections. The crossthreads then consist of one long thread woven back and forth. Thisconsequently is doubled 0r looped at the edges and this results invarious objections. The looped end when it is sharply doubled back islikely to break and fray, especially when run through the guides, andgive passage atmospheric moisture in the threads as well as the pores ofthe fibers themselves. Most (ribbons are run in a substantially verticalplane, and one edge rests on the guides. It therefore soon wears andfrays. Also, the frayed ends soil the paper, catch on the guides, andare otherwise objectionable.

Cotton is very hygroscopic. If a narrow ribbon having cross threads withthe ends not looped but raw (cut ofi') and untreated, were used, thedefects of the doubled ends would in part be avoided, but other evenmore objectionable results would occur.- Atmospheric moisture passes, asin the above illustration of a frayed looped thread, resulting invarious troubles such as decay, contraction of one or both edges, and anuneven or possibly wrinkled ribbon which will not lie flat and whichbrings still more friction thereon in the guides, and the ribbon soongoes to pieces at its edge. A typewriter ribbon usu-ally comes in aclosely fitting tin box, the ribbon itself being further protected by awrapping of tinfoil. These precautions to a great extent protect theribbon until it is put on the machine, but once in use it is exposed tothe atmospheric moisture, which greatly varies in quantity, andconsequently the ribbon usually has a short life. I have discovered thata ribbon principally composed of fine animal fiber, preferably silk,when properly treated as herein described, results in one which hasseveral advantages, and avoids Objections inherent in ribbons of theprior art. By silk I do not mean necessarily entirely composed of silk.

I prefer to use a fine closely woven silk from 3 to 5 one thousand-thsof an inch thick, in a strip substantially the width of the completedribbon, and with the cross threads raw (cut) at each end. A portion ofsuch a strip is shown in Fig. let A. The strip may be cut from a widesheet. I may smooth, calender, or iron the fabric, but this is notalways necessary. I- also prefer that the threads be loosely twisted,because theribbon will wear longer than when they are hard or tightlytwisted. It is also more absorbent of ink.

Then I impregnate the raw ends of the threads with a fluid or liquid gumwhich is flexible and substantially non-hygroscopic when dried. Thislays the ends and binds them continuously to each other, as shown at E,F, in Fig. 1, and, what is important,

prevents passage of moisture in the ends of as flexible as the silkalone.

thereto a small quantity of glycerin or its equivalent to make theresultant gum mixture more flexible when dried. The fluid gum may beapplied by passing the strip between pressure rollers C, D, as shown inFig. 2-, if desired, the gum bein fed to the rollers or by a rotaryknife suita ly gummed. The strip is then dried.

Rawsilk is very hygroscopic. In its natural or untreated state it hasconsiderable ceresin in Or on it. I prefer to remove this, or aconsiderable amount of it, as I find the ribbon resulting has a bettersurface, takes ink more readily and in greater quantity, the threadsslip on each other, and has other advantages Also, the gum seems, to setor take hold of thefibers better. The ceresin may be removed, preferablybefore weaving,

by boiling the silk in a soft-Water (nonalkali) soap solution.

The ribbon made as above is perfectly flat, is substantiallynon-hygroscopic at its edges, takes ink readily, and is not so subjectto contraction or other defects due to moisture. .Its edges whenproperly treated are firm and smooth, and'will not so readily wear out,but yet are almost, if not quite, It has other advantages. v

I am aware that my invention may be em- .bodied in avariety of formsother than the examples above given, and the. claims hereto appended arenot intended to be limited to all the details heretofore described. WhatI claim is:

1. A ribbon of the character described, I

comprising a strip of thin fabric made of fine animal fiber, eachcross-thread terminating in a raw end at each edge of the strip, and acontinuous flexible dried gum impregnated in said raw ends along eachedge, thereby binding each raw end to the others and closing the ends ofthe threads against passage of moisture.

. 2. A ribbon of the character described, comprising a strip of thinsilk, each crossthread terminating in a raw end at each edge of thestrip, and a continuous flexible dried gum impregnated in said raw endsalong each edge, thereby binding each raw end to the others and closingthe ends of the threads against passage of moisture.

3. A ribbon of the character described, comprising a strip of thin silkfrom which the'ceresin has been at least partially, removed, eachcross-thread terminating in a raw end at each edge of the strip, and acontinuous flexible dried gum impregnated in said raw ends" along eachedge, thereby binding each raw end to the others and closing the ends ofthe threads against passage of moisture.

4. A ribbon of the character described,

comprising a strip of thin fabric made of animal fiber loosely twisted,each crossthread terminating in a raw end at each edge of the strip, anda continuous flexible driedgum impregnated in said raw ends along eachedge, thereby binding each raw end to the others and closing the ends ofthe threads against passage of moisture. v

Signed at New York city, N. Y., this-8th day of May, 1919. l

' JACOB A. L. 'MOLLER;

